As this type of apparatus, there has been suggested an apparatus which responds to the abnormality of a rotary valve in an engine which uses the rotary valve as an intake control valve (e.g. refer to a patent document 1). According to the rotary valve engine disclosed in the patent document 1 (hereinafter referred to as a “conventional technology”), a cylinder closed by the rotary valve is identified and fuel supply to the closed cylinder is stopped on the basis of the detection signal of a rotation angle sensor attached to the rotary valve. Thus, even if the rotary valve is abnormally stopped, troubles caused by an accidental fire, a standing fuel, and the like will be likely dissolved. Moreover, at this case, a connection path, which is appropriately connected to each intake path which is connected to each cylinder, in accordance with the rotation angle of the rotary valve, is configured to open one of the said intake paths always. Thus, even if the rotary valve is abnormally stopped, an engine stop will be likely avoided.
Incidentally, there has been also suggested such an apparatus that when the failure of the rotary valve is detected, an intake air amount is controlled by a rotary valve which is not broken, with the broken rotary valve fixed at an open position (e.g. refer to a patent documents 2).
Moreover, there has been also suggested a technology of stopping the fuel supply to the cylinder that fails in the opening and closing operation and of increasing a fuel supply amount to the remaining cylinders, in a pulse supercharging valve provided for each cylinder (e.g. refer to a patent document 3).    Patent Document 1: Japanese Patent Application Laid Open No. Hei 3-229946    Patent Document 2: Japanese Patent Application Laid Open No. Hei 11-324687    Patent Document 3: Japanese Patent Application Laid Open No. Hei 4-330331